Shock absorber for drilling machines



Feb. 14, 1939. GRANDFIELD 2,147,436

SHOCK ABSORBER FDR DRILLING MACHINES Original Filed March 10, 19s? 2 Sheets-Sheet 1 m .I): I I! i I 8 9 V I! on. a 4 38d '4 I (9 i h7' ""l I I: If I I I! I ,g 3 25 Inventor Attorneys Feb. 14, 1939.

MGRANDFIELD SHOCK ABSORBER FOR DRILLING MACHINES Original Filed March 10, 1937 2 Sheets-Sheet 2 Inventor Attorneys Patented Feb. 14, 1939 SHOCK ABSORBER FOR. D'RELLHNG MACHINES Earl M. Grandfielcl, Boynton, Okla.

Application March 10, 1937, Serial No. 130,176 Renewed May 31, 1938 5 Claims.

My invention relates to improvements in shock absorbers for use on drilling rigs in the drilling and spudding of oil wells.

The invention is designed primarily to provide efficient practical means readily attachable to the usual drilling rig to reduce to a negligible degree the shock on the usual drilling and jerk lines incident to drilling and spudding and whereby the life of the rig drilling machinery and said lines is prolonged.

Other objects of my invention are to provide shock absorbing means which will render practicable increasing the reach and fall of the drilling tool as compared with present equipment, thereby expediting the drilling operation.

Another object is to provide shock absorbing means for the purposes above set forth and by virtue of which the ordinary spudding lines may be eliminated.

Still other objects are to provide means for the purpose above indicated which are strong and durable, and economical to manufacture.

To the accomplishment of the above, and subordinate objects presently appearing, a preferred embodiment of my invention has been illustrated in the accompanying drawings, set forth in detail in the following description, and defined in the claims appended hereto.

In the drawings:----

Figure 1 is a View in side elevation illustrating conventionally an oil rig equipped according to my invention,

Figure 2 is a fragmentary View in side elevation of a portion of the floor of the rig, the floor supporting sills, and my improved shock absorbing means,

Figure 3 is a fragmentary view in rear elevation,

Figure 4 is a View in longitudinal section taken on the line 4-4 of Figure 2.

Describing the illustrated embodiment of my invention, with reference to the drawings by numerals, l designates the usual oil well rig or derrick, embodying a rig floor, or platform 2, and floor supporting sills 3. At the rear side of the rig I adjacent to the floor 2 is the usual reel 4 for the drill line 5 which is coiled around said reel 4, in a manner and for a purpose well known, led up over a crown pulley 6 on top of the rig l for extension into the drill casing i. The numeral 8 designates the usual jerk line for use in spudding slidably attached at one end to the drill line, adjacent to the reeled up end thereof, by means of a sleeve-like shoe 9 through which said drill line 5 extends. The jerk line 8 is actuated in a manher well understood in the art through the men presently described, to incline rearwardly and 10' upwardly toward the reel 4, a pulley H5 at the opposite end of said cylinder under which the drill line 5 is led from the reel i to form a bight in said line, a draw-bar it extending from the opposite end of said cylinder, a clevis ll securing the 15:

pulley it to the extended end of said draw-bar iii, shock absorbing compression springs l8 in said cylinder for opposing movement of the drawbar it outwardly of the cylinder l4, and a rebound compression spring lll cushioning rebound 20 of said bar.

Describing now the before mentioned mounting, the cylinder l is closed at its mounted end by a head 29 provided with an outwardly extending lug 2i pivoted, as at 22, between the ears 23 of a sleeve 24, the latter freely mounted on-a shaft 25 secured at its opposite ends to the undersides of appropriate floor sills 3, by clips 25 and bolts 21, to extend parallel with the axis of the reel 4. The sleeve 24 is adjustably secured on the shaft 25, by set collars 28, in substantially the plane of the reel 4. The axis of the pivot 22 it will be noted lies at a right angle to that of the sleeve 24 so that the cylinder M and pulley H": are free for compensating movement about both axes under the pull of the drill line 5.

The clevis I! is pivotally mounted, as at 29, on the outer end of the draw bar 16 for additional compensating movement thereof in the plane of the bight of the drill line 5. The clevis i1 is hookshaped to provide a bearing at both ends for a pulley supporting bolt iii. A leaf spring 30 extends from said clevis to the edge of the pulley l5 to form a retaining guide preventing the line 5 from jumping out at the open side of said clevis.

The draw bar it at its inner end is provided with a piston-like head 3! in which the draw bar is adjustably mounted by nuts 32 threaded on said bar. The outer end of said bar 56 extends 50 through a bearing sleeve 32 suitably secured in a cylinder head 33 retained in the outer end of the cylinder by bolts 34. A reinforcing band 35 surrounds the cylinder I 4 opposite the head 33 and is secured in place by the bolts 35.

The shock absorbing springs I8, of which there are three, are interposed between the draw bar head 3| and the cylinder head 33 and separated by disks 36. The rebound spring I3 is interposed between a disk 31, loosely mounted on the outer end of the draw bar [6, and the cylinder head 33. The rebound spring I9 obviously is potentially less reactive than the springs IS. The arrangement of the disk 31 is such that it bears under the urge of the rebound spring l9 against square ends on the clevis I1 thereby yieldingly aligning said clevis with the draw bar 16 so that under a slack in the drill line 5 said clevis and the pulley l5 will not flop over on the draw bar. It is contemplated that the cylinder [4 be filled with lubricant, such as oil. Therefore, a drain plug 38 is threaded into the lower end of the cylinder M for draining said cylinder to renew the oil or other lubricant. It will be understood that the draw bar I6, head 3| and the disks 36 are constructed to permit the passage of oil between the same and the inner wall of the cylinder M, for instance, by being loosely fitted in said cylinder.

A pair of compression springs 39 suitably connected at their opposite ends to the cylinder I4 and floor 2, respectively, as at 4! and 4|, yieldingly sustain the cylinder 14 in the before described upwardly inclined position and in a vertical plane to facilitate passing the drill line 5 under the pulley l5 and to prevent the device from falling down when a slack occurs in the bight of the drill line 5 or when the device is not in use.

From the foregoing it will be understood that under the pull of the jerk line and drill line the rod I6 is moved outwardly of the cylinder M against the tension of the springs 18 whereby the shocks upon the various operating parts and the strain on said jerk and drill lines 8 and 5 is reduced to a minimum. By virtue of the described mounting for the device the latter under the pull of the drill line 5 is free to follow side play of said line as it pays off the reel 4. The rebound spring IS absorbs the shock and jar on the pulley l5 and clevis l1 incident to retraction of the pull rod If: as well as functioning in the manner previously described to align said pulley and clevis. By means of the set collars 28, the device may be located in the desired position on the shaft 28 without resetting the mounting shaft 25 and the securing means therefor.

Manifestly details and arrangements of parts described in the foregoing may be modified without departing from the inventive concept disclosed and it is to be understood that right is herein reserved to all such modifications falling within the scope of the claims appended hereto.

What I claim is:-

1. In apparatus of the class described, the combination with a drill line, a reel for said line, and a jerk line operatively connected to said drill line, of shock absorbing means for said lines including a cylinder mounted at one end to extend upwardly toward said reel and for pivotal movement about right angularly related axes, a pulley at the upper end of said cylinder under which the drill line extends intermediate the point of connection of the jerk line thereto and said reel, said pulley being slidably mounted in said cylinder for movement outwardly thereof and tensioned against outward movement.

2. In apparatus of the class described, the combination with a drill line, a reel for said line, and a jerk line operatively connected to said drill line, of shock absorbing means for said line including a cylinder mounted at one end to extend upwardly toward said reel and for pivotal movement about right angularly related axes, a pulley at the upper end of said cylinder under which the drill line extends intermediate the point of connection of the jerk line thereto and said reel, said pulley being slidably mounted in said cylinder for movement outwardly thereof and tensioned against outward movement, and resilient means for tensioning the cylinder against movement from upright position.

3. In apparatus of the class described, the combination with a drill line, a reel therefor, and a jerk line operatively connected to said drill line, of shock absorbing means for said lines including a shaft fixedly mounted below said reel parallel with the axis thereof, a cylinder extending from said shaft upwardly toward said reel and mounted at its lower end on said shaft for pivotal and sliding movement thereon, a pulley at the upper end of said cylinder under which the drill line extends intermediate the point of connection of the jerk line thereto and said reel, said pulley being slidably mounted in said cylinder for movement outwardly thereof under the pull of the drill line and tensioned for movement inwardly of said cylinder, and means for cushioning movement of said pulley inwardly of said cylinder.

4. In apparatus of the class described, the combination with a drill line, a reel therefor, and a jerk line operatively connected to said drill line,

of shock absorbing means for said lines including a shaft fixedly mounted below said reel parallel with the axis thereof, a sleeve freely mounted on said shaft, a cylinder extending upwardly from said sleeve toward said reel and pivotally mounted at its lower end on said sleeve for movement about an axis right angularly related to the axis of said shaft, a pulley at the upper end of said cylinder under which the drill line extends intermediate the point of connection of the jerk line thereto and said reel, said pulley being slidably mounted in said cylinder for movement outwardly thereof under pull exerted on said drill line and tensioned for movement inwardly of said cylinder, and means for cushioning inward movement of said pulley.

5. A shock absorbing device for drill lines comprising a shaft adapted to be mounted in fixed position, a sleeve freely mounted on said shaft, a cylinder pivotally connected at one end to the sleeve for movement about an axis at a right angle to the axis of the shaft, a draw bar slidably mounted in said cylinder for movement inwardly and outwardly of the cylinder and extending from one end thereof, means in said cylinder for tensioning said bar against outward movement, a clevis pivotally mounted on the extending end of said bar for movement thereon into and out of alignment therewith, a compression spring interposed between said clevis and cylinder for cushioning the inward movement of said bar, said spring cooperating with the inner end of said clevis to yieldingly align the latter with said bar, and a pulley mounted in said clevis.

EARL M. GRANDFIELD. 

